Question
Evalute : $\int x e^{2 x} d x$

Answer

$
\begin{aligned}
\int x e^{2 x} d x & =x \int e^{2 x} d x-\int\left[\frac{d}{d x}(x) \int e^{2 x} d x\right] d x \\
& =x \cdot \frac{e^{2 x}}{2}-\int 1 \cdot \frac{e^{2 x}}{2} d x \\
& =\frac{1}{2} x e^{2 x}=\frac{1}{2} \int e^{2 x} d x \\
& =\frac{1}{2} x e^{2 x}-\frac{1}{2} \cdot \frac{e^{2 x}}{2}+c \\
& =e^{2 x}\left(\frac{x}{2}-\frac{1}{4}\right)+c \\
& =\left(\frac{2 x-1}{4}\right) e^{2 x}+c .
\end{aligned}
$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free